Comparison of Surgical Wound Infection after Preoperative Skin Preparation with 4% Chlohexidine and Povidone Iodine: A Prospective Randomized Trial Veeraya Paocharoen MD*, Chatchai Mingmalairak MD*, Anucha Apisarnthanarak MD** * Department of Surgery, Faculty of Medicine, Thammasat University, Bangkok, Thailand ** Infectious Unit, Department of Medicine, Faculty of Medicine, Thammasat University, Bangkok, Thailand

Background: Antiseptic scrub and paint can reduce bacterial colonization and postoperative wound infection. Two forms of antiseptics, povidone iodine and chlorhexidine, are commonly used in the operating theater. Objective: To study the efficacy of the reduction of bacterial colonization and surgical wound infection among these antiseptic. Material and Method: Five hundred surgical patients were randomly divided into two groups. Povidone Iodine and Chlorhexidine were used for skin preparation in group 1 and 2 respectively. Bacterial colonization and postoperative wound infection were examined after skin preparation. Demographic data was analyzed by student’s t test; the culture result and surgical wound infection were analyzed by Mantel-Haenszel method for relative risk and 95% CI. Results: There was a significant reduction of bacterial colonization and wound infection after skin preparation in group 2 compared with group 1. Conclusion: Colonization of bacterial and postoperative surgical wound infection were significantly reduced in the chlorhexidine group. Chlorhexidine antiseptic should be the first consideration for preoperative skin preparation. Keywords: Chlorhexidine, Povidone-iodine, Skin, Surgical wound infection J Med Assoc Thai 2009; 92 (7): 898-902 Full text. e-Journal: http://www.mat.or.th/journal

Surgical wound infections are infections of the tissues, organs, or spaces exposed by surgeons during performance of an invasive procedure(1). The use of preoperative skin preparation by effective antiseptic plays an important role in reducing postoperative wound infection. There are several kinds of antiseptics available for preoperative skin preparation. However, chlorhexidine gluconate in isopropyl alcohol and povidone iodine are commonly used and convenient in clinical practice. Bacterial colonization at the skin and wound infection are reduced by several antiseptic agents under the different pharmacologic Correspondence to: Paocharoen V, Department of Surgery Faculty of Medicine Thammasat University Rangsit Campus, Klong nung, Klong luang, Pathumthani 12120, Thailand.

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actions. A previous study showed that chlorhexidine in alcohol provided better result in the reduction of bacterial contamination of the skin in foot and ankle operation(2). One study showed that chlorhexidine gluconate was more effective than povidone iodine in decreasing the bacterial colony counts that were found in the operative field for vaginal hysterectomy(3). The meta-analysis confirmed that the incidence of blood stream infections was significantly reduced in patients with central vascular lines who received chlorhexidine gluconate versus povidone iodine for insertion-site skin disinfection(4). However, there has not been a comparative study between chlorhexidine and povidone iodine antiseptic skin preparations in general surgery patients.

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Material and Method The present study was approved by the Human Research Ethic Committee of Thammasat University. Five hundred patients in the department of surgery between June 2006 and November 2008 were enrolled in the present study. Inclusion criteria were age 18-60 years, clean, clean contaminated and contaminated wounds and ASA class 1 and 2. The exclusion criteria were patient refusal, dirty wound, uncontrolled diabetes, on immunosuppressive drugs, serum albumin less than 3.0 mg/dl, and history of allergy to study agent. The patients were divided into two groups randomly. Group 1 was the povidone iodine group; 5 minutes scrubbed by povidone iodine scrub solution followed by povidone iodine paint. Group 2 was the 4% chlorhexidine in 70% isopropyl alcohol; 5 minutes scrubbed by hibitane scrub solution followed by hibitane paint. Skin swab culture was performed at the pretended incision site after skin preparation. Specimens were transferred to the laboratory by stewart transport media and were swabbed into blood or McCongee agar plates within 24 hours. The agars were incubated in 37 degree Celsius oven. The plates were examined every 24 hours until 3 days. The authors allowed other preoperative preparations under the standard guideline. The surgical wounds were examined twice a week in the first week and every week up to 1 month. An incisional surgical site infection had occurred if a surgical wound drained purulent material or if the surgeon judges it to be infected and opens it(1). Demographic data was analyzed by student’s test. The culture result and surgical wound infection were analyzed by Mantel-Haenszel method for relative risk and 95% confidence interval of relative risk. Results Five hundred patients were enrolled in the present study. The demographic data is shown in

Table 1. These patients were divided into two groups. Group 1, included 250 patients (122 females, 138 males), was the povidone iodine group and group 2 (250 patients, 91 females and 159 males) was the chlorhexidine in alcohol group. The mean age was 56.2 years (20-79) in group 1 and 50.5 years (18-78) in group 2. There was no significant statistical difference of the age between the two groups (p-value = 0.27). The average operation time was 1.43 hours (40 min-3 hours) in group 1 and 1.45 hours (45 min-3 hours) in group 2 (p-value = 0.93). The wounds were classified into class 1 (clean wound), class 2 clean contaminated wound, and class 3 contaminated wound in both groups. In group 1, 87 (34.8%) were clean wounds, 112 (44.8%) were clean contaminated wounds, and 51 (20.4%) were contaminated wound. In group 2 96 (38.4%), 118 (47.2%) and 46 (18.4%) were clean, clean contaminated, and contaminated wounds respectively. There were no significant statistical differences in terms of wound types between the two groups (p-value = 0.91) (Table 1). There was a significant reduction of bacterial colonization after skin preparation in group 2 compared with group 1 (14.4% vs. 31.2%). Relative Risk was 2.69, and 95% Confidence Interval Relative Risk was 2.15-3.55 (Table 2). The organisms found in the culture specimen included Streptococcus epidemidis, Staphylococcus aurers, Streptococcus sp., and Enterococci sp. The bacterial colonizations reduced significantly after skin preparation in all types of organisms as shown in Table 2. There were eight cases (3.2%) of surgical wound infection in group 1. The culture showed staph. aureus in five cases (2%); four from Arterio-Venous Shunt operation, one from Modified Radical Mastectomy operation. The Enterococci spp. was found in two cases (0.8%) in this group; one from appendectomy and one from gastrectomy operation. The remaining was E. coli was found in appendectomy operation (0.4%). In group 2,

Table 1. Demographic data n

Mean age (years) Operative time (hours) No. of wound class (%) No. of gender

Group 1 (povidone iodine)

250

56.2 (20-79)

1.43 (40 min-3 hr)

Group 2 (chlorhexidine)

250

50.5 (18-78)

1.45 (45 min-3 hr)

p = 0.27

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p = 0.93

I II III I II III

87 (34.8) 112 (44.8) 51 (20.4) 96 (38.4) 118 (47.2) 46 (18.4) p = 0.91

Female 122 Male 138

Female 91 Male 159

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Table 2. Post-op colonization (> 103 CFU/ml)*

Group 1 n = 250

Group 2 n = 250

RR**

95% CI RR***

Total [no.(%)] S. epidermidis S. aureus Streptococcus sp. Enterococcus sp.

78 (31.2) 53 (14.4) 7 (2.8) 18 (7.2) 1 (0.4)

36 (21.2) 26 (10.4) 3 (1.2) 7 (2.8) -

2.69 2.31 2.37 2.69

2.15-3.55 1.91-2.70 2.08-2.65 2.34-3.03

Group 2

RR*

* Colony forming unit ** Relative risk *** 95% confidence interval relative risk

Table 3. Postoperative surgical wound infection Group 1 Postoperative infection [no.(%)] Organism [no.(%)] S. aureus Enterococcus sp. E. coli Bacteroides fragilis

8 (3.2)

5 (2)

5 (2) 2 (0.8) 1 (0.4) -

3 (1.2) 1 (0.4) 1 (0.4)

1.61

95% CI RR** 1.40-1.81

* Relative risk ** 95% confidence interval relative risk

five cases (2%) had surgical wound infection. Staph. aureus were found in three cases (1.2%); two from Arterio-Venous Shunt operation, one from appendectomy operation. E. coli was found in one case (0.4%) from right half colectomy operation. A case of Bacteroides fragilis was also found in Appendectomy wound. The statistical significant reduction of surgical wound infection was demonstrated in group 2 patients; RR 1.61 (1.40-1.81) (Table 3). In addition, there were two cases of skin irritation from povidone iodine scrub in group 1 patients but there was no allergic reaction to chlorhexidine detected in group 2 patients. Discussion The development of surgical site infections is related to three factors, 1) the degree of bacterial contamination during the operation, 2) the duration of procedure, and 3) underlying diseases of the patients such as immune deficiency, diabetes, and malnutrition(1). Preoperative skin preparation is one of the important local factors concerning the development of surgical site infection. In the present study, the authors

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controlled risk factors for development of surgical site infection except preoperative skin preparation using two different antiseptic agents. According to Table 1, there was no significant statistical difference of the risk factors between the two groups of the sample patients such as age, operative time, wound classification, or underlying host factors. The authors standardized the two groups of sample by the inclusion criteria. The authors also prepared both groups under the same standard guidelines. Gram-positive bacteria was the predominant organism on the skin. The authors demonstrated that pharmacologic action against gram-positive organism of chlorhexidine might be superior to povidone iodine. There was significant statistical difference in the colonization reduction in the chlorhexidine group. The colonization count, mainly gram-positive organism, was reduced more in the chlorhexidine group than povidone iodine group. In addition, wound infection could be decreased from 3.2% to 2% after chlorhexidine skin preparation. However, some cases were infected by gram-negative bacilli or anaerobic organism such as Enterobacter in appendectomy and gastrectomy, E. coli in right half

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colectomy, or Bacteroides fragilis in appendectomy. Normal flora at the skin should be gram-positive organism such as Staph. spp. or Strep spp. Therefore, it should consider that some wound infections occur by the surgical technique such as microspillage from the intestinal content that cannot be totally prevented by skin antiseptic only. Color staining and hypersensitivity are another disadvantage of povidone iodine solution. There is no report of hypersensitivity in the chlorhexidine group in the present study.

4.

5.

6. Conclusion The present study suggests that colonization of the bacteria is significantly reduced in the chlorhexidine group. Post-operative surgical wound infection is also reduced in chorhexidine group. Other disadvantages of using povidone iodine are hypersensitivity and color staining. Chlorhexidine antiseptic should be the first consideration for preoperative skin preparation.

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8. References 1. Dunn DL, Beilman GJ. Surgical infections. In: Brunicardi FC, Andersen DK, Billiar TR, Dunn DL, Hunter JG, Matthews JB, et al, editors. Schwartz’s principles of surgery. 8th ed. New York: McGrawHill; 2005: 109-28. 2. Bibbo C, Patel DV, Gehrmann RM, Lin SS. Chlorhexidine provides superior skin decontamination in foot and ankle surgery: a prospective randomized study. Clin Orthop Relat Res 2005; 438: 204-8. 3. Culligan PJ, Kubik K, Murphy M, Blackwell L, Snyder J. A randomized trial that compared

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povidone iodine and chlorhexidine as antiseptics for vaginal hysterectomy. Am J Obstet Gynecol 2005; 192: 422-5. Chaiyakunapruk N, Veenstra DL, Lipsky BA, Saint S. Chlorhexidine compared with povidoneiodine solution for vascular catheter-site care: a meta-analysis. Ann Intern Med 2002; 136: 792-801. Hibbard JS. Analyses comparing the antimicrobial activity and safety of current antiseptic agents: a review. J Infus Nurs 2005; 28: 194-207. Meier DE, Nkor SK, Aasa D, OlaOlorun DA, Tarpley JL. Prospective randomized comparison of two preoperative skin preparation techniques in a developing world country. World J Surg 2001; 25: 441-3. Shindo K, Funai S, Kuroda K, Wakano T, Nishimura K. Clinical study on the antiseptic effect of povidone-iodine solution for the surgical field of digestive tract operations. Dermatology 2002; 204 (Suppl 1): 47-51. Ostrander RV, Botte MJ, Brage ME. Efficacy of surgical preparation solutions in foot and ankle surgery. J Bone Joint Surg Am 2005; 87: 980-5. Mimoz O, Karim A, Mercat A, Cosseron M, Falissard B, Parker F, et al. Chlorhexidine compared with povidone-iodine as skin preparation before blood culture. A randomized, controlled trial. Ann Intern Med 1999; 131: 834-7. Mangram AJ, Horan TC, Pearson ML, Silver LC, Jarvis WR. Guideline for Prevention of Surgical Site Infection, 1999. Centers for Disease Control and Prevention (CDC) Hospital Infection Control Practices Advisory Committee. Am J Infect Control 1999; 27: 97-132.

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การศึกษาแบบสุม่ ไปข้างหน้าเพือ่ เปรียบเทียบการติดเชือ้ ในแผลผ่าตัดระหว่างการเตรียมผิวหนัง เพือ่ การผ่าตัดด้วยสารละลาย chlorhexidine 4% และ povidone iodine วีรยะ เภาเจริญ, ฉัตรชัย มิง่ มาลัยรักษ์, อนุชา อภิสารธนรักษ์ ภูมิหลัง: การเตรียมผิวหนังเพื่อการผ่าตัดเป็นขั้นตอนสำคัญแต่ยังไม่มีผู้ศึกษาถึงการใช้ chlorhexidine 4% สำหรับ การเตรียมผิวหนังเพื่อการผ่าตัดในแผนกศัลยกรรมมาก่อน วัตถุประสงค์: เพื่อเปรียบเทียบการลดจำนวนแบคทีเรีย และการติดเชื้อหลังผ่าตัดของแผลผ่าตัด ระหว่างการเตรียม ผิวหนังด้วย chlorhexidine 4% และ povidone iodine วัสดุและวิธีการ: ผู้ป่วยที่เข้ารับการผ่าตัดในภาควิชาศัลยศาสตร์ คณะแพทยศาสตร์มหาวิทยาลัยธรรมศาสตร์ จำนวนรวม 500 คน จะถูกแบ่งเป็น 2 กลุม่ กลุม่ ละ 250 คน กลุม่ หนึง่ ได้รบั การเตรียมผิวหนังด้วย povidone iodine ส่วนอีกกลุม่ ได้ chlorhexidine 4% ผูป้ ว่ ยได้รบั การตรวจหา จำนวนเชือ้ แบคทีเรียทีย่ งั เหลือบนผิวหนัง และการติดเชือ้ หลังผ่าตัดที่แผลผ่าตัด ผลการศึกษา: ผู้ป่วยทั้งสองกลุ่มมีลักษณะพื้นฐานไม่แตกต่างกัน จำนวนแบคทีเรียบริเวณแผลผ่าตัดในกลุ่มที่ได้รับ การเตรียมแผลด้วย chlorhexidine 4% ลดลง มากกว่ากลุ่มที่ได้รับ povidone iodine อย่างมีนัยสำคัญทางสถิติ นอกจากนี้กลุ่ม chlorhexidine 4% ยังมีการติดเชื้อที่แผลผ่าตัดน้อยกว่ากลุ่ม povidone iodine สรุป: การเตรียมผิวหนังที่จะผ่าตัดด้วย chlorhexidine 4% สามารถลดจำนวนแบคทีเรียที่ผิวหนัง และลดอัตรา การติดเชื้อหลังผ่าตัดบริเวณแผลผ่าตัด ได้มากกว่าการเตรียมด้วย povidone iodine

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